What’s in a name…


Unprecedented warming and the ‘Hockey Stick’ controversy


Current atmospheric change at unprecedented rates


Dutch Elfstedentocht: February 1985


NOAA: climate at a glance

How warm has is gotten? (Ed Hawkins)


https://www.youtube.com/watch?v=jWoCXLuTIkI


Global combined land and ocean-surface temperature was 0.93 of a degree C above the 20th-century average for July 2021. Northern Hemisphere land-surface temperature was the highest ever recorded for July 2021, 1.5°C above average

Physical impacts of climate change are visible


Last decade reveals smallest sea ice extents

The argument for humans as the culprit (pop’n = 7.98 billion)


Haber-Bosch process (1909) and human population


Greenhouse gases (ice cores) correlate to warming


Greenhouse gases: Carbon dioxide (CO2)


Global Change and Water are intimately linked



Global Change: Fresh Water Scarcity for 2/3’s of the world


Global Change: Ocean acidification has multiple feedbacks


Global Change: Sea Level Rise


Paris Climate Agreement



  • Accord between nation in UN to address climate change


  • Goal to keep increase in global temperature below 2 °C
    • pursue efforts to limit increase to 1.5
    • pursue net zero emissions


  • Contributions by country determined by that country
    • no emissions targets or dates
    • must go beyond current efforts
    • framework for transparency

Are targets of the Paris Climate Agreement reachable?


What should we do….




  • If CO2 emissions stopped today:
    • 50% absorbed by land/water in 30 yrs
    • 30% in atmosphere for centuries
    • 20% in atmosphere for 1000 yrs


  • Future warming is inevitable
    • land sinks uncertain
    • ocean sinks weakening


  • Negative emissions techology?